Green chemicals from pulp production black liquor by partial wet oxidation

Raja Hassan, Kristian Melin, Daniela Del Carmen Villalba de Kokkonen, Gerard Viader Riera, Golam Sarwar, Jukka Koskinen

Research output: Contribution to journalArticleScientificpeer-review

14 Citations (Scopus)


To reduce greenhouse gas emissions, more sustainable sources of energy, fuel and chemicals are needed. Biomass side streams such as black liquor, which is a by-product of pulp production, has the potential to be used for this purpose. The aim of the study was the production of carboxylic acids, such as lactic acid, formic acid and acetic acid, from kraft and non-wood black liquor. The processes studied were partial wet oxidation (PWO) and catalytic partial wet oxidation (CPWO). The results show that the yield of carboxylic acid is higher when treated by PWO than the results from CPWO at temperatures of 170 degrees C and 230 degrees C. The results shows that the PWO process can increase the yield of carboxylic acids and hydroxy acids in black liquor, reduce lignin content and decrease pH, which makes further separation of the acids more favourable. The hydroxy acids are valuable raw materials for biopolymers, and acetic acid and formic acid are commonly used chemicals conventionally produced from fossil feedstock.

Original languageEnglish
Pages (from-to)1015-1021
Number of pages7
JournalWaste management and Research
Issue number11
Publication statusPublished - Nov 2015
MoE publication typeA1 Journal article-refereed


  • Wet oxidation
  • catalytic wet oxidation
  • partial wet oxidation
  • black liquor
  • spent liquor
  • soda non-wood cooking liquor
  • pulp and paper waste treatment


Dive into the research topics of 'Green chemicals from pulp production black liquor by partial wet oxidation'. Together they form a unique fingerprint.

Cite this